UC-NRLF 


103 


GIFT  OF 
Class   of   1887 


PKIZE   ESSAY. 


OX    T  II  K 


CHEMICAL    CONSTITUTION 


THE  BILE. 


r.Y 


EDWARD    R.   TAYLOR,  M.  I) 


CALIFORNIA. 


Divide  et  Impera. 


EXTRACTED    FROM    THE 
TRANSACTIONS    OF    THE    AMERICAN    MEDICAL     ASSOCIATION. 


P  II  LLAUELPH  JA: 
COLLINS,  PRINTER,  705    JAYNE    STREET. 

1871. 


PRIZE   ESSAY. 


ON    THE 


CHEMICAL 


OP 


THE  BILE. 


BY 


EDWARD   R.  TAYLOR,  M.  D. 


CALIFORNIA. 


Divide  et  Impera, 


EXTRACTED    FROM    THE 
'RANSACTIONS    OF    THE    AMERICAN    MEDICAL     ASSOCIATION 


PH ILADELPHIA: 
COLLINS,  PRINTER,  705   JAYNE    STREET 

1871. 


"  'Tis  hard,  I  confess,  yet,  nevertheless,  I  will  adventure 
through  the  midst  of  these  perplexities,  and  led  by  the  clue 
or  thread  of  the  best  writers,  extricate  myself  out  of  a  laby- 
rinth of  doubts  and  errors." 

BURTON'S  Anatomy  of  Melancholy . 


PRIZE   ESSAY. 


THE  CHEMICAL  CONSTITUTION  OF  THE  BILE. 


THE  bile  is  the  most  complex  of  all  the  juices,  whether  we  con- 
sider its  chemical  nature  or  the  purposes  it  subserves  in  the  animal 
economy.  The  former  has  been  more  satisfactorily  investigated 
by  Strecker  than  by  any  other  physiological  chemist,  his  discovery, 
in  1848,  of  the  resinous  salts  being  beyond  question  a  great  step  in 
advance.  Much,  however,  remains  yet  to  be  done  in  this  direction, 
for  while  we  can  form  some  idea  as  to  how  and  where  urea,  creatine, 
creatinine,  and  the  like,  are  formed,  we  are  almost  in  the  dark  as  to 
the  tauro-cholic  and  glyco-cholic  acids.  The  physiology  of  the  bile 
is  more  obscure  even  than  its  chemistry.  Indeed,  we  really  'know 
but  little  about  it,  and  we  therefore  still  sail  upon  the  sea  of  conjec- 
ture. 

Bile,  as  it  is  obtained  from  the  gall-bladder,  is  a  thick,  ropy, 
viscid  fluid,  varving  in  specific  gravity  and  color  in  different  ani- 
mals, the  former  being  in  man  about  1018,  and  the  latter  being 
dark  golden-brown  according  to  some,  and  greenish-yellow  accord- 
ing to  others.  Dalton  fixes  the  specific  gravity  of  human  bile  at 
1018,  ox  bile  at  1024,  and  pig's  bile  at  1030  to  1036.  In  chemical 
reaction  it  is  found  to  be  sometimes  neutral,  sometimes  alkaline, 
but  very  rarely  acid.  It  possesses  antiseptic  properties,  and  to  this 
is  attributed  the  fetor  of  the  feces  in  some  diseases,  especially  cholera, 
in  which,  owing  to  a  general  cessation  of  the  secretions,  the  bile 
does  not  flow  into  the  intestine.  Its  taste  is  excessively  disagree- 
able and  quite  bitter,  the  after-taste  being  sweetish ;  and  its  odor 
peculiarly  nauseous,  being  likened  by  Lehmann,  especially  when 
warmed,  to  that  of  musk.  Owing  to  the  contained  mucus,  it  is 
susceptible  of  being  drawn  into  threads  (Lehmann} ;  and  it  "  froths 
up  into  a  soap-like  foam  when  shaken  in  a  test-tube,  or  when  air 


PRIZE    ESSAY: 


is  forcibly  blown  into  it  through  a  small  glass  tube  or  blowpipe  ; 
the  bubbles  of  foam  thus  produced  remain  for  a  long  time  without 

to  each  other  and  to  the  sides  of  the 


gla_ss..yesse,r  \Jbalt6n}.  'It.  is  stated  by  Todd  and  Bowman,  that 
by~4^dd$i$rQi  o3f;biJe/^.tte  blood,  coagulation  is  either  retarded 
or  prevented.  This  is  accounted  for  on  the  ground  of  its  affording 
a  "  mechanical  obstacle"  to  the  "  cohesion  of  the  particles  of  fibrin." 
It  has  been  said  that  bile  undergoes  rapid  decomposition  when  out 
of  the  body,  but  Pavy  denies  this,  and  asserts  that  such  is  the  case 
only  with  weak  or  poor  bile ;  and  that  rich  bile  dries  up  on  expo- 
sure to  the  atmosphere,  without  showing  signs  of  decomposition. 
The  following  analysis  of  the  composition  of  the  bile  of  the  ox  is 
from  Dalton's  physiology : — 

Water .        .      880.00 

Glyco-cholate  of  soda        .         .         .         .        ]         QA  00 
Tauro-cholate  of  soda  1 

Biliverdin  (coloring  matter)  ] 

Fats         .        .         .        .        .) 

Oleates,  margarates,  and  stearates  of  soda,  and  }•         13.42 
potassa         .        .         .        ... 

Cholesterine 

Chloride  of  sodium ~) 

Phosphate  of  soda 

"  lime 15.24 

"  "  magnesia    .... 

Carbonates  of  soda  and  potassa 
Mucus  of  gall-bladder      .....  1.34 

1000.00 

"Urea  occurs  in  the  bile  in  urasmia,"  and  "  albumen  is  found  in 
the  embryonic  state,  occasionally  in  fatty  liver,  in  Bright's  disease, 
and  in  abscess  of  the  liver"  (Lehmann). 

Dr.  Kernp  gives  the  following  analysis  of  the  elementary  pro- 
portions in  the  compound  resulting  from  the  union  of  the  biliary 
organic  principles  with  soda  (choleic  acid  of  Demarcay): — 


CHEMICAL    CONSTITUTION    OF    BILE. 

Carbon 59.90 

Hydrogen 8.90 

Nitrogen 3.40 

Oxygen .  17.63 

Sulphur .  3.10 

Soda 6.53 

Chloride  of  sodium   .  0.54 


100.00 
(Budd  on  the  Liver) 

The  following  percentages  of  the  solid  constituents  of  the  bile 
of  different  animals  are  taken  from  West's  Dictionary  of  Chemistry: 
"In  normal  human  bile,  Frerichs  found  14  per  cent.,  or  rather 
more,  of  solid  constituents;  Gorup-Besanez,  in  the  bile  of  two 
recently  executed  criminals,  found  10.19  and  17.73  per  cent,  solid 
matter ;  in  that  of  an  old  man,  9.13  per  cent. ;  and  in  that  of  a  boy 
twelve  years  old,.  17.19  per  cent.  Ox  bile  contains  10.13  per  cent, 
solid  constituents;  pig's  bile,  10.6  to  10.18  per  cent.  (Gorup-Besanez 
and  Streck&r)-  dog's  bile,  5.1  per  cent.;  cat's  bile,  5.6  per  cent. 
(Bidder  and  Schmidt)]  sheep's  bile,  5.13 ;  rabbit's  bile,  1.8;  goose 
bile,  6.9 ;  kangaroo's  bile,  14.13;  and  crow's  bile,  7.3  per  cent,  solid 
constituents."  According  to  this,  human  bile  is  considerably 
richer  in  solid  constituents  than  that  of  many  animals,  and  some- 
what richer  than  that  of  the  ox  and  pig.  This  latter  is  not  quite 
reconcilable  with  the  specific  gravities  above  given,  for  they  would 
seem  to  show  the  reverse  to  be  the  case. 

The  fats,  scaps,  and  inorganic  salts  of  the  bile  require  no  men- 
tion, though,  as  regards  the  latter,  it  is  a  curious  and  important 
fact  that  in  the  bile  of  salt-water  fishes  the  potassa  salts  predomi- 
nate, while  in  that  of  fresh-water  fishes  the  soda  salts  predominate. 
This  was  first  noticed  by  Bensch,  but  was  more  fully  investigated 
by  Strecker  (Draper  and  Lehmann). 

Cholepyrrhine,  the  name  given  by  Berzelius  to  the  coloring  matter 
of  the  bile,  is  a  highly  carbonaceous,  uncrystallizable  substance, 
containing  a  small  quantity  of  nitrogen  and  iron ;  but  its  chemistry 
has,  as  yet,  been  so  unsatisfactorily  investigated,  that  little  is 
known  of  its  composition  or  properties.  According  to  Lehmann, 
the  original  pigment  is  cholepyrrhine,  a  brownish  substance,  the 
biliverdin  of  Berzelius  being  the  result  of  its  oxidation.  Berzelius 
thought  that  the  bile  pigment  was  composed  of  two  coloring 
matters,  on  account  of  the  precipitation  of  biliverdin  from  a  soda 


8  PRIZE    ESSAY: 

or  potassa  solution  of  cholepyrrhine,  on  the  addition  of  an  acid,  but 
the  view  of  Lehmann  is  now  thought  to  be  correct;  and  the 
various  colors  presented  by  bile  are  all  probably  dependent  upon 
modifications  of  cholepyrrhine  (Kirke).  After  its  entrance  into  the 
intestine,  the  bile  pigment  is  changed  into  a  yellowish  matter, 
which  is  so  different  from  the  original  pigment,  that  nitric  acid  no 
longer  brings  out  the  play  of  colors  so  peculiar  to  the  coloring 
matter  of  the  bile.  It  is  easily  decomposed,  so  much  so  that  it  is 
extremely  difficult  to  obtain  it  pure;  it  is  sparingly  soluble  in 
most  fluids,  its  best  solvent  being  a  solution  of  soda  or  potassa 
(Todd  and  Bowman).  In  jaundice,  we  find  the  bile  pigment  in 
various  secretions,  especially  the  urine,  and  in  the  blood.  It  forms 
a  large  proportion  of  biliary  concretions,  being  generally  associated 
in  these  with  lime  and  cholesterine.  From  the  researches  of 
Brarnson,  it  would  seem  that  it  forms  with  the  former  of  these  a 
definite  compound.  Its  origin  has  been  pretty  well  made  out  to 
be  from  the  hsematin  of  the  blood-cell.  Lehmann  says  that  when 
the  bile  is  long  retained  in  the  gall-bladder,  there  is  produced  a 
substance  precisely  similar  to  hasmatoidine ;  and  Yirchow,  in  his 
cellular  pathology,  remarks  that  hasmatoidine  is  the  only  substance 
in  the  body  with  which  we  are  acquainted,  that  is  allied  to  the  bile 
pigment.  "  By  the  direct  action  of  mineral  acids,  or  after  previous 
treatment  and  preparation  by  means  of  alkalies,  the  same,  or  pre- 
cisely similar  color  tests,  are  obtained,  which  are  yielded  by  the 
coloring  matter  of  the  bile,  when  treated  with  mineral  acids ;  and 
it  seems  also,  from  other  facts,  that  we  have  here  a  body  before  us 
which  is  very  intimately  connected  with  the  coloring  matter  of 
the  bile."  He  further  remarks  that  in  the  interior  of  extravasations 
there  arises  a  "yellowish-red  substance  which  may  be  designated 
as  a  newly-formed  kind  of  biliary  coloring  matter."  In  a  case  of 
cancer  of  the  head  of  the  pancreas  in  which  the  common  duct  was 
obstructed,  I  observed  that  the  bile  in  the  gall-bladder  was  inspis- 
sated (owing,  no  doubt,  to  its  long  retention  there),  and  in  color  was 
ruby-red.  This  hue  resulted  from  a  concentration  of  yellow  (pre- 
cisely as  is  seen  in  the  case  of  the  blood),  this  being  readilv  shown 
by  the  experiment  of  diluting  a  small  quantity  of  the  inspissated 
bile.  Frerichs  contests  the  above  views,  and  maintains  that  no  one 
has  succeeded  in  manufacturing  bile  pigment  from  the  red  color- 
ing matter  of  the  blood.  On  the  contrary,  he  holds  that  the 
biliary  acids  are  the  source  of  the  bile  pigment,  and  that  the 
jaundice  incident  to  pyaemia,  and  to  many  of  the  fevers,  is  owing 


CHEMICAL    CONSTITUTION    OF    BILE.  9 

I  to  an  incomplete  metamorphosis  of  the  bile  in  the  blood,  and  that 
"thus  a  sufficient  quantity  of  bile  pigment  remains  in  the  blood  to 
give  rise  to  all  the  symptoms  of  jaundice."  In  fact,  by  the  con- 
tinued action  of  sulphuric  acid  upon  glyco-cholic  acid,  he  asserts 
that  a  substance  is  produced  whose  reactions  are  the  same  as  those 
of  cholepyrrhine.  The  like  result  is  obtained  with  the  resinous 
salts.  He  injected  colorless  solutions  of  bile  into  the  veins  of 
dogs,  and  while  Pettenkofer's  test  failed  to  show  the  biliary  acids, 
nitric  acid  brought  out  all  the  play  of  colors  characteristic  of  bile 
pigment.  Ktihne,  however,  maintains  that  the  biliary  acids  do 
constitute  a  part  of  the  urine  in  these  cases,  and  says  that  the 
reasoo  of  their  apparent  absence  is  because  of  the  Pettenkofer  test 
not  being  sufficiently  accurate.  He  claims  to  have  detected  the 
acids  by  means  of  the  more  delicate  test  of  Hoppe,  and  says  that 
when  the  biliary  acids  or  their  salts  are  injected  into  the  veins, 
they  pass  out,  as  a  rule,  unchanged.  Should  any  bile  pigment  be 
found,  he  explains  its  presence  by  reason  of  the  dissolution  of  blood- 
corpuscles  by  the  biliary  acids  and  the  consequent  setting  free  of 
hasmatin,  from  which  latter  is  produced  the  biliary  coloring 
matter.  Frerichs,  from  certain  experiments  in  his  laboratory  (as 
we  learn  from  the  translator's  preface  to  his  clinical  treatise  on  the 
liver),  "  admits  that  there  is  an  intimate  relation  between  bile  pig- 
ment and  the  coloring  matter  of  the  blood,  and  even  thinks  it  pro- 
bable that  the  former  substance  may  be  developed  from  the  latter," 
but  still  holds  to  his  former  belief  that  the  biliary  acids  are  con- 
vertible into  bile  pigment.  Murchison,  in  his  clinical  lectures  on 
the  liver,  leans  towards  the  views  of  Frerichs.  Niemeyer,  how- 
ever, holds  the  views  of  Klihiie  to  be  well  established,  for  he  says 
in  the  seventh  edition  (1869)  of  his  practical  medicine  (I  quote 
from  Humphrey's  and  Hackley's  translation),  that  the  biliary  acids 
"  possess  to  a  peculiar  degree  the  property  of  dissolving  the  red 
blood-corpuscles.  By  injecting  weak  solutions  of  them  into  the 
blood  of  animals,  we  may  artificially  induce  the  so-called  hasma- 
togenous  icterus  (jaundice  without  reabsorption),  as  the  liberated 
coloring  matter  of  the  blood  is  transformed  into  biliary  coloring 
matter.  *  *  *  *  *  The  views  regarding  the  occurrence  of  jaundice 
without  retention  and  reabsorption  of  bile  have  totally  changed 
since  the  observations  of  Virchow,  Kuhne,  and  Hoppe-Leyler  have 
shown  that  bile  coloring  matter  may  be  formed  from  the  free 
coloring  matter  of  the  blood  without  the  action  of  the  liver ;  and 
•e  may  induce  artificial  jaundice  in  animals  by  injecting  substances 


we  ma^ 


10  PRIZE    ESSAY: 

that  dissolve  the  blood-corpuscles.  There  is  now  no  doubt  that 
some  of  the  formerly  enigmatical  forms  of  icterus  are  due  to  the 
disintegration  of  the  freed  coloring  matter  circulating  in  the  blood, 
into  bile  coloring  matter."  Besides,  the  iron  that  both  contain 
would  point  directly  to  a  close  kinship  between  them.  It  would 
seem,  therefore,  that  we  may  finally  rest  upon  the  belief  that  the 
source  of  the  cholepyrrhine  of  the  bile  is  the  ha3matin  of  the  blood. 

The  resinous  salts,  as  they  are  called,  glyco-cholate  and  tauro-cho- 
late  of  soda,  are,  beyond  question,  the  most  important  of  the  biliary 
ingredients',  and  form,  with  cholesterine,  the  essential  constituents  of 
the  bile.  As  will  be  seen  by  reference  to  the  analysis  above  given, 
they  constitute  75  per  cent,  of  the  biliary  solids.  These  two^salts, 
as  chemically  described,  exist  only  in  the  bile  of  the  ox,  for,  as  has 
been  well  shown  by  Dalton,  there  are  minor  differences  to  be  found 
in  them  in  the  bile  of  various  species  of  animals.  Their  re- 
actions are  not  the  same  with  the  acetate  and  snbacetate  of  lead ; 
in  some,  the  glyco-cholate  crystallizes  much  more  slowly  than  it 
does  in  ox  bile,  while  in  others,  in  human  bile  for  instance,  it  does 
not  crystallize  at  all.  These  substances  are  obtained  from  the  bile 
of  the  ox  by  first  evaporating  it  to  dryness,  and  then  extracting 
with  absolute  alcohol  the  resinous  salts  in  conjunction  with  fats 
and  coloring  matter;  the  former  are  then  obtained  by  treating  the 
filtered  solution  with  ether,  which  precipitates  them,  while  the 
latter  are  dissolved.  On  standing  for  some  little  time  in  a  test- 
tube,  the  glyco-cholate  of  soda  is  seen  to  shoot  out  in  needle-like 
crystals,  while  the  tauro-cholate  remains  in  an  amorphous  condi- 
tion somewhat  resembling  the  globules  of  oil.  They  can  be  sepa- 
rated from  each  other  by  reason  of  their  different  reactions  with 
the  acetate  and  subacetate  of  lead  (Dalton).  We  collate  from 
West's  Dictionary  of  Chemistry  that  the  tauro-cholate  of  soda  pre- 
ponderates largely  over  the  glyco-cholate  in  man,  while  the  reverse 
is  the  case  in  the  ox  and  the  pig  ;  in  almost  all  other  animals  the 
tauro-cholate  has  the  preponderance. 

The  glyco-cholate  of  soda  crystallizes  from  its  solution  in  radia- 
ting bundles  ot  fine,  white  silky  needles  (Dalton).  The  soda  being 
displaced  by  sulphuric  acid,  we  have  the  glyco-cholic  acid  (cholic 
of  Strecker)  set  free.  Its  formula  is  given  as  C52H42NOU.  It  crys- 
tallizes in  needles,  and  has  a  bitterish-sweet  taste  (Fowne).  When 
boiled  in  a  solution  of  potassa,  it  separates  into  two  substances, 
cholic  acid  (cholalic  of  Strecker)  and  glycine;  and  when  boiled  in 
concentrated  sulphuric  or  muriatic  acid,  the  glycine  is  still  pro- 


CHEMICAL    CONSTITUTION    OF    BILE.  11 

duced,  but  the  acid  loses  one  atom  of  water  and  becomes  choloidic 
cid.  Dalton,  in  opposition  to  most  physiological  chemists,  does  not 
ook  upon  glyco-cholic  acid  as  being  a  conjugated  compound,  but 
akes  the  ground  that  the  cholic  acid  and  glycine  are  merely  new 
ombinations  of  its  elements  produced  by  long  boiling  in  contact 
vith  potassa  and  water.  To  this  view  there  are  serious  objections. 
The  Pettenkofer  test  brings  out  precisely  the  same  colors  when 
pplied  to  the  cholic  acid  as  it  does  when  applied  to  the  glyco. 
holic  or  tauro-cholic,  which  could  scarcely  be  the  case  were  the 
atter  not  conjugated  acids  with  the  former  as  a  principal  adjunct. 
Besides,  in  the  decomposition  of  hippuric  acid  we  have  as  marked 
an  example  of  the  separation  of  glycine  as  we  have  in  the  conju- 
;ated  acids  of  the  bile,  this  acid,  when  heated  with  concentrated 
nitric  or  muriatic  acid,  separating  into  benzoic  acid  and  glycine. 
.'his  latter,  however,  is  thought  by  Lehmann  to  be  formed  from 
umaramide  (arnide  of  fumaric  acid),  the  glycine  not  existing  pre- 
brmed  in  the  hippuric  acid.  His  opinion  is  founded  upon  the 
act  that  anhydrous  glycine  (C4H4N03)  + anhydrous  benzoic  acid 
C14HS03),  yields  one  atom  more  of  each  hydrogen  and  oxygen  than 
anhydrous  hippuric  acid  contains.  Those  who  take  the  ground 
hat  the  glycine  exists  preformed  (and  the  weight  of  opinion  seems 
o  preponderate  this  way),  give  to  the  hippuric  acid  an  equivalent 
>f  water,  making  their  formula,  C18H8N05HO.  The  glycine, 
•esulting  from  the  decomposition  of  this  acid,  is  the  same  as  pro- 
duced by  the  decomposition  of  glyco-cholic  acid,  and  may  be 
btained  artificially  by  boiling  gelatine  with  a  strong  solution  of 
3otassa,  which  yields  at  the  same  time  a  substance  called  leucine. 
Phis  might  lead  one  to  point  to  the  metamorphosis  of  the  gelati- 
ious  (connective)  tissues  as  the  source  of  glycine  in  the  animal 
body;  but,  as  Lehmann  well  remarks,  the  metamorphosis  going  on 
n  these  tissues  is  entirely  too  insignificant  to  account  for  the 
xmount  of  glycine  (or  fumaramide)  contained  in  the  hippuric  or 
^lyco-cholic  acids.  He,  therefore,  refers  its  origin  to  the  regressive 
netamorphosis  of  effete  nitrogenous  tissues,  being  analogous  in  this 
•espect  to  urea.  To  be  sure,  the  latter  has  been  found  in  the 
)lood,  while  nothing  resembling  glycine  has  been  there  discovered ; 
)ut  we  must  have  consideration  for  the  many  difficulties  accompa- 
lying  the  procurement  from  the  blood  of  excrementitious  substances, 
is  well  as  for  the  fact  that  there  is  a  large  amount  of  uninvestigated 
natters  put  down  as  extractive,  a  knowledge  of  which  will  one  day 
hrow  light  on  many  places  that  are  now  dark.  These  extractives, 


12  PRIZE    ESSAY: 

according  to  Lehmann's  analysis,  amount  to  as  much  as  2.60  parts 
in  1000  in  the  corpuscles,  and  8.94  parts  in  1000  in  the  liquor  san- 
guinis.  Pig's  bile  differs  from  that  of  all  other  animals  examined, 
in  that  the  glyco-cholic  acid  is  replaced  by  an  acid  analogous  to 
it,  and  known  as  hyocholic.  This  latter  differs  from  the  glyco- 
cholic  in  having  two  atoms  more  of  carbon,  one  more  of  hydrogen, 
and  one  less  of  oxygen.  It  has  never  been  found  elsewhere  than 
in  the  bile  of  the  pig  (Lehmanri). 

The  Tauro-  Cholate  of  Soda  is  an  uncrystallizable  substance,  though 
Lehmann  claims  to  have  crystallized  it.  As  has  been  mentioned, 
it  exists  in  larger  quantity  in  most  animals  than  the  glyco-cholate. 
The  tauro-cholic  acid  (choleic  of  Strecker  and  bilin  of  other 
chemists)  is  best  obtained  by  decomposing  the  tauro-cholate  of 
soda  with  subacetate  of  lead,  and  treating  the  tauro-cholate  of  lead, 
thus  produced,  with  sulphide  of  hydrogen  (Fowne).  It  is  said, 
however,  never  to  have  been  obtained  in  a  perfectly  pure  state. 
Its  formula  is  given  as  C52H  NS20]4.  It  does  not  crystallize, 
is  more  soluble  in  water  than  glyco-cholic  acid,  and  does  not  pos- 
sess such  strong  acid  properties.  It  dissolves  the  fatty  acids,  fats, 
and  cholesterine,  which  will  account  for  these  substances  being 
held  in  solution  in  the  bile.  Boiled  with  the  alkalies,  or  mineral 
acids,  it  exhibits  the  same  reactions  as  glyco-cholic  acid,  with  the 
exception  that  taurine  instead  of  glycine  is  developed;  and  the 
same  remarks  will  apply  to  its  conjugation  as  were  made  respect- 
ing that  acid. 

The  soda,  with  which  the  glyco-cholic  and  tauro-cholic  acids  are 
united  in  the  bile,  is  believed  to  be  derived  almost  altogether  from 
the  chloride  of  sodium  of  the  ingesta.  This  is  decomposed  in  the 
stomach,  the  chlorine  uniting  with  the  hydrogen  of  water,  and  form- 
ing hydrochloric  acid  (the  essential  acid  of  digestion),  and  the  so- 
dium laying  hold  of  the  oxygen,  and  furnishing  the  soda  for  the  bile. 
Granted  that  the  glyco-cholic  and  tauro-cholic  acids  are  conju- 
gated compounds,  we  are  brought  to  the  consideration  of  the  gly- 
cine, taurine,  and  cholic  acid,  the  most  important  inquiries  being  as 
to  their  source  and  mode  of  formation.  Indeed,  to  succeed  in  this 
would  be  to  answer  the  vital  question  relating  to  the  chemistry  of 
the  bile.  Before  entering  upon  this,  perhaps  it  would  be  well  to 
make  a  brief  examination  of  some  of  the  physical  properties  of 
these  interesting  substances.  Lehmann's  great  work  on  physio- 
logical chemistry  being  mainly  relied  upon  as  authority. 

Glycine,  or  sugar  of  gelatine,  or  glycocoll  (C4H4N03),  is  a  ni- 


CHEMICAL    CONSTITUTION    OF    BILE.  13 

trogenous  substance,  as  its  formula  indicates,  and  has  a  sweetish 
taste,  but  no  odor.  It  readily  dissolves  in  cold  water,  but  is  almost 
insoluble  in  absolute  alcohol,  and  quite  so  in  ether.  It  is  easily 
decomposed  by  electrolysis,  there  being  an  alkaline  reaction  at  the 
negative,  and  an  acid  reaction  at  the  positive  pole.  This  inclined 
Horsford  to  the  opinion  that  it  was  a  salt-like  compound  with  am- 
monia as  a  base4  but  Strecker  puts  it  down  as  the  amide  of  glycic 
acid,  which  Lehmann  thinks  to  be  correct.  As  stated  above,  it 
may  easily  be  obtained  from  gelatine,  from  hippuric  and  glyco- 
cholic  acids.  According  to  Lehmann,  it  does  not  exist  preformed 
in  these  acids,  but  is  produced  pretty  much  in  the  same  manner  as 
is  glycerine  from  the  oxide  of  lipyl,  which,  in  the  process  of  saponi- 
fication,  takes  up  an  atom  of  water  immediately  on  being  set  free, 
and  becomes  the  hydrated  oxide  of  lipyl,  or  glycerine. 

Taurine  (C4H7NS206)  is  a  crystallizable,  hard  substance,  charac- 
terized by  its  containing  the  sulphur  which  is  found  in  the  bile, 
as  much  as  25  per  cent,  of  the  taurine  being  made  up  of  this 
element.     When  burned  in  the  open  air,  it  evolves  sulphurous 
acid.    It  has  a  cooling  taste,  but  no  odor,  and  its  solubility  is  about 
the  same  as  that  of  glycine.    Redtenbacher  thought  it  to  be  a  com- 
bination of  sulphurous   acid  with   aldehyde   and    ammonia,  and 
attempted  to  produce  it  artificially  by  passing  the  acid  into  an 
alcoholic  solution  of  aldehyde  ammonia;    but  though  he  failed,  a 
substance  was  obtained  by  him  isomeric  with,  and  very  much  re- 
sembling taurine.    With  the  isethionate  of  ammonia,  Strecker  was 
more  successful.    By  driving  off  its  water,  and  treating  the  residue 
with  alcohol,  crystals  of  taurine  were  produced.      This  can  be 
readily  understood  by  examining  the  formula.     Fowne  gives  that 
of  isethionic  acid  as  C4H5O2S03;    add  ammonia  to  this,  and  we 
have  C4H302S03NH3;  or,  to  write  it  in  another  way,  C4H807S2N. 
It  is  seen,  therefore,  that  by  the  subtraction  of  the  elements  of 
one  atom  of  water,  we  have   expressed  the  formula  of  taurine. 
As  to  the  formation  of  isethionic  acid,  we  learn  from  Gregory  that 
"  when  anhydrous  acid  S03  acts  on  alcohol,  or  when  olefiant  gas 
is  absorbed  by  that  dry  acid,  there  is  formed  a  compound,  2S034- 
C4H4  in  crystals,  which,  when  put  into  cold  water,  produce  ethi- 
onic  acid;  when  this  solution  is  heated,  2  equivalents  of  sulphuric 
acid  and  1  of  alcohol  separate  from  one-half,  and  there  is  formed 
from  the  other  half  isethionic  acid."     Thus,  from  such  familiars  as 
sulphuric  acid,  alcohol,  and  ammonia  has  man  been  able  to  manu- 
facture one  of  the  most  complex  substances  in  the  animal  organism  I 
2 


14  PKIZE    ESSAY: 

i 

Taurine  has  not  been  found  isolated  in  normal  conditions,  but  has 
been  so  found  in  decomposed  or  morbid  bile.  The  moist  tests  for 
sulphur  failing  to  show  it  in  the  bile,  it  is  presumed  that  this  ele- 
ment exists  in  the  taurine  in  an  oxidized  state ;  but  the  chemistry 
of  this  substance  is  still  very  obscure.  In  the  bile  it  is  conjugated 
with  cholic  acid,  forming  the  tauro-cholic  acid. 

Cholic  acid,  cholalic  acid  of  Strecker  (C48H3909HO),  called  by 
Carpenter  the  "  fundamental  component  of  bile,"  is  a  crystallizable, 
hard  substance,  characterized  by  its  containing  no  nitrogen,  a  small 
proportion  of  oxygen,  and  a  very  large  proportion  of  carbon — as 
much  as  70|  parts  in  100  being  made  up  of  this  element.  It  is 
soluble  in  sulphuric  acid;  but,  unlike  taurine  and  glycine,  it  is 
difficultly  soluble  in  water,  while  it  dissolves  in  alcohol  and  ether. 
When  boiled  for  some  time  with  hydrochloric  acid,  it  loses  an 
atom  of  water,  and  with  it  its  power  of  crystallization,  becoming 
choloidic  (choloidinic)  acid.  If  the  boiling  be  longer  continued, 
this  acid  is  changed  into  dyslysin — so  called  from  its  difficult  solu- 
bility. By  the  action  of  nitric  acid  cholic  acid  is  converted  into 
capric,  caprylic,  and  cholesteric  acids  (Day).  Cholic  acid  is 
assumed  by  Lehrnann  to  be  a  conjugated  oleic  acid,  whose  adjunct 
(C12H606)  is  polymeric  with  cholesteric  acid  (C8H404).  Eedten- 
bacher  obtained  this  latter  substance  by  the  decomposition  of 
choloidic  acid.  Having  briefly  passed  in  review  some  of  the  pro- 
perties of  glycine,  taurine,  and  cholic  acid,  let  us  now  inquire 
into  something  of  what  is  known  of  their  origin. 

The  afferent  vessels  of  the  liver  are  the  portal  vein  and  the 
hepatic  artery— the  latter  a  branch  of  the  cceliac  axis,  while  the 
former  is  made  up  of  the  superior  and  inferior  mesenteric,  the 
splenic  and  gastric  veins,  which  receive  the  blood  from  the  in- 
testines, the  stomach,  and  the  spleen.  It  is  probable,  as  is  asserted 
by  some  (though  denied  by  others),  that  the  portal  vein  contains 
freshly  digested  matters  from  the  stomach ;  and  not  only  this,  but 
fat  from  the  small  intestine.  This  latter  has  been  established  by 
the  observations  of  Kolliker.  He  noticed  that  some  hours  after 
ingestion,  sucking  animals  have  invariably  a  fatty  liver.  "  While 
of  the  same  litter  of  animals  some  are  made  to  fast,  while  others 
are  allowed  to  suck,  those  which  have  sucked  have  a  fatty  liver  a 
few  hours  afterwards,  whilst  the  others  have  not"  ( Virchow).  This 
fat  could  not  come  from  the  stomach,  because  we  very  well  know 
that  this  organ  does  not  act  upon  the  fats  at  all,  and  that  they  are 
rendered  absorbable  elsewhere.  It  has  also  been  pretty  well 


CHEMICAL    CONSTITUTION    OF    BILE.  15 

established,  experimentally,  that  the  veins  have  the  predominance 
over  the  lacteals  in  the  absorption  of  sugar  from  the  small  intestine. 
That  the  bile  is  not  solely  derived  from  the  portal  vein  is  proved 
by  the  experiment  of  its  ligation,  in  which  case  the  secretion  still 
goes  on,  though  in  much  diminished  quantity.  But,  at  the  same 
time,  this  experiment,  together  with  the  fact  that  the  hepatic  artery 
does  not  have  more  than  one-eighth  the  area  of  the  portal  vein, 
proves  that  the  portal  system  is  the  chief  source  of  the  biliary 
secretion  (  Carpenter).  Draper  believes  the  bile  to  be  derived  alto- 
gether from  systemic  venous  blood,  and  "  not  from  the  products 
of  digestion  obtained  from  the  chylopoietic  viscera."  He  thinks 
it  inconceivable  that  products  obtained  from  the  digestive  tract 
should  be  returned  so  soon  thereto,  and  he  cites  the  meconium  of 
the  foetus  as  absolute  proof;  this  being  a  true  bile  according  to  the 
analysis  of  Simon,  and  secreted  before  the  system  knows  anything 
of  digestion.  But  there  can  be  nothing  "  inconceivable"  in  believing 
that  freshly  digested  matters  may  be  returned  into  the  intestine  in  a 
metamorphosed  shape,  for  the  purpose  of  assisting  in  the  digestion 
of  other  matters,  or  for  the  ulterior  purpose  of  performing  other 
service  in  the  economy.  And  as  to  the  meconium,  it  is  not  at  all 
probable  that  the  biliary  secretion  in  the  foetus  is  the  same  as  it 
becomes  after  birth.  But,  at  the  same  time,  one  thing  is  certain : 
it  is  no  proof  that  the  constituents  of  bile  do  not  pre-exist  in  the 
blood  because  they  have  not  been  found  there.  Our  chemico-ana- 
lytical  investigations  are  beset  with  difficulties  that  science  has  as 
yet  been  unable  to  overcome;  and  we  should  further  take  into 
consideration  the  possible  small  quantity  of  bile  as  compared  with 
that  of  the  circulating  blood.  Liebig,  in  his  Animal  Chemistry, 
remarks,  on  this  point,  that  "if  we'suppose  8^  pounds  (58,000  gr.) 
of  blood  to  pass  through  the  liver  every  minute,  and  if,  from  this 
quantity  of  blood,  2  drops  of  bile  (3  gr.  to  the  drop)  are  secreted, 
this  would  amount  to  se'^th  part  of  the  weight  of  the  blood — a 
proportion  far  too  small  to  be  quantitatively  ascertained  by  ana- 
lysis." 

The  cholic  acid  of  the  bile  is  held  by  Lehmann  to  be  manufac- 
tured in  the  liver  from  fat  and  sugar.  The  former  gives  up  its 
oleic  acid,  and  the  latter,  on  conjugation,  is  assumed  to  part  with  6 
atoms  of  water.  We  have  seen  that  the  portal  blood  is  well  sup- 
plied with  these  substances ;  and  when  we  take  into  consideration 
the  fact  that  olein,  with  proper  care,  gives  the  same  reaction  with 
Pettenkofer's  test  as  cholic  acid  ;  that  the  hepatic  veins  are  poorer 


16  PRIZE  ESSAY: 

in  oily,  and  richer  in  solid  fat,  than  the  portal  vein ;  and  that  Ked- 
tenbacher  obtained  from  choloidic  acid  (which,  as  has  been  men- 
tioned, is  cholic  acid  less  one  atom  of  water),  when  treated  with 
nitric  acid,  the  same  volatile  acids  that,  under  similar  circumstances, 
were  obtained  from  oleine ;  the  view  of  Lehmann  seems  very  rea- 
sonable, and  has  much  to  support  it.  Schmidt,  however,  has  a 
modification  of  it  which  is  very  ingenious.  He  derives  both  cholic 
acid  and  sugar  from  neutral  fat,  by  replacing  one-seventh  of  the 
hydrogen  of  glycerine  with  one  atom  of  oxygen,  which  gives  the 
formula  for  anhydrous  grape  sugar  ;  and  by  assuming  that  seven  of 
the  equivalents  of  hydrogen  of  the  solid  fatty  acid  are  replaced  by 
oxygen,  which  gives  the  formula  for  cholic  acid  (Lehmann).  Now, 
as  an  excess  of  fat  and  a  deficiency  of  sugar. enter  the  liver,  while 
these  conditions  are  reversed  as  they  leave  it,  and  as  we  know  that 
the  liver  produces  sugar  in  large  quantity,  Schmidt's  view  is  cer- 
tainly not  unreasonable.  Lehmann  gives  his  opinion  the  prefer- 
ence over  that  of  Schmidt,  for  these  reasons:  "Unconjugated  acids 
containing  nine  atoms  of  oxygen  are,  at  all  events,  very  rare  in 
chemistry;  oleic  acid  yields  the  ordinary  reaction  with  Petten- 
kofer's  test,  which  is  not  the  case  with  the  solid  fatty  acids ;  and 
(what  is  of  more  importance)  there  is  far  less  oily  fat  (although  rela- 
tively more  solid  fat)  in  the  hepatic  venous  blood  than  in  that  of 
the  portal  vein."  Day,  in  his  Physiological  Chemistry,  agrees  with 
Lehmann  as  to  cholic  acid  being  formed  from  oleic  acid  and  sugar, 
and  remarks,  that  "  a  comparison  of  the  respective  products  of  oxi- 
dation of  cholic  and  oleic  acids  strengthens  the  hypothesis;  for 
when  treated  with  concentrated  nitric  acid,  cholic  acid  yields  pre- 
cisely the  same  products  of  decomposition  as  oleic  acid,  and  addi- 
tionally a  carbo-hydrate,  namely,  cholesteric  acid,  whose  com- 
position is  represented  by  the  formula  C8H404."  So  far  as  the 
herbivora  are  concerned,  Liebig  thinks  he  has  proved  that  the 
non-azotized  products  of  digestion  assist  in  the  formation  of  the 
bile.  He  endeavors  to  show  that  the  carbon  of  the  bile,  in  these 
animals,  is  in  larger  amount  than  if  it  preserved  its  proper  propor- 
tions to  nitrogen  as  one  of  the  constituents  in  the  metamorphosis 
of  nitrogenous  tissue,  and  though  there  is  much  doubt  as  to  the  ox 
secreting  so  large  an  amount  of  bile  in  twenty-four  hours  as  thirty- 
seven  pounds,  still  the  secretion  is  probably  not  sufficiently  small 
to  overthrow  Liebig's  calculation.  The  elements  of  starch  furnish, 
he  thinks,  the  non-nitrogenous  constituents  of  bile,  and  he  shows 
that  by  the  separation  of  oxygen  and  the  elements  of  water,  cholo- 


CHEMICAL    CONSTITUTION"    OF    BILE.  17 

idic  acid  may  be  formed  from  starch.  For  instance,  if  from  six 
atoms  of  starcb  we  take  forty-four  atoms  of  oxygen  and  four  atoms 
of  water,  we  have  remaining  the  formula  of  choloidic  acid  (Liebig's 
Animal  Chemistry).  That  his  views  on  this  point  are  essentially 
the  same  as  those  of  Lehmann,  it  is  only  necessary  to  quote  a  short 
extract  from  him :  "  Chemical  analysis  and  the  study  of  the  living 
animal  body  mutually  support  each  other;  and  both  lead  to  the 
conclusion  that  a  certain  portion  of  the  carbon  of  the  non-azotized 
constituents  of  food  (of  starch,  etc.,  the  elements  of  respiration)  is 
secreted  by  the  liver  in  the  form  of  bile."  All  this  agrees  with 
what  has  been  before  stated  as  to  the  portal  vein  containing  freshly 
digested  matters  from  the  chylopoietic  viscera. 

As  to  the  taurine  #nd  glycine,  physiological  chemists  are  well 
agreed  that  they  are  formed  from  the  regressive  metamorphosis  of 
nitrogenous  tissue,  but  the  how  and  the  where  remain  yet  to  be 
determined.  The  most  careful  manipulation  has  failed  to  detect 
their  presence,  or  anything  analogous  to  them,  or  any  substance 
containing  them,  in  the  blood  of  the  portal  vein.  Still,  for  reasons 
heretofore  mentioned,  there  is  a  possibility  of  their  having  an  ex- 
istence there.  We  know  that  when  the  liver  is  unable  to  perform 
its  functions,  nitrogenous  substances,  possessing  higher  atomic 
numbers  than  glycine  and  taurine,  are  found  abundantly  in  the 
liver  and  urine.  In  acute  yellow  atrophy,  and  in  other  cases  of 
acholia,  large  quantities  of  leucine  and  tyrosine  have  been  so  dis- 
covered (Frerichs).  Now,  this  fact  alone  would  point  to  the  liver 
as  the  seat  of  formation  of  glycine  and  taurine,  and  to  the  almost 
absolute  certainty  of  their  being  formed  from  the  regressive  meta- 
morphosis of  nitrogenous  tissue.  It  has  been  thought  that  the 
sulphuric  acid  of  the  portal  blood  gives  origin  to  the  sulphur  of 
taurine ;  but  while  some  chemists  have  found  more  of  this  acid  in 
the  portal  blood  than  in  that  of  the  hepatic  veins,  other  chemists, 
Lehmann  for  one,  have  found  the  reverse.  This  latter  chemist 
has,  however,  found  considerably  more  sulphur  in  the  portal  blood 
than  in  that  of  the  hepatic  veins,  and  he  succeeded  in  obtaining  an 
extract  from  the  former  which  was  very  rich  in  this  element. 
Still,  he  inclines  to  the  opinion  that  the  greater  part  of  the  sulphur 
of  the  bile  is  derived  from  the  "  perfect  disintegration  of  fibrin  in 
the  liver."  The  blood  undoubtedly  undergoes  great  changes  in  its 
passage  through  this  gland,  among  them  being  its  loss  of  albumen 
and  fibrin,  and  its  proportionate  gain  of  corpuscles.  The  former, 


18  PRIZE    ESSAY: 

Lehmann  thinks,  builds  up  the  walls  of  the  latter  (they  in  the 
blood  of  the  hepatic  veins  containing  no  sulphur),  while  the  fibrin 
is  disintegrated  and  contributes  to  the  formation  of  the  bile.  This 
is  in  accordance  with  what  is  pretty  well  established  as  to  albumen 
being  the  parent  of  all  the  tissues,  and  with  what  is  believed  by 
many,  that  fibrin  is  the  first  product  of  the  metamorphosis  of 
albumen.  In  the  liver,  the  fibrin,  already  on  the  downward  course, 
may  be  decomposed  into  other  regressive  products  that  are  worked 
up  into  the  bile.  We  know  that  fibrin,  when  boiled  in  hydro- 
chloric acid,  yields  tyrosine  and  lucine,  and,  as  has  been  mentioned, 
that  these  substances  accumulate  in  the  liver  and  urine  when  the 
functions  of  the  liver  are  arrested.  Again,  as  is  believed  by  Dra- 
per and  others,  the  glycine  and  taurine  may  be  formed  in  the  ulti- 
mate tissues,  as  are  urea,  creatine,  and  the  like,  and  be  conveyed  to 
the  liver  as  are  the  latter  to  the  kidneys,  escaping  detection  in  the 
blood.  Liebig  has  attempted  by  paper  formulae  to  show  how 
various  excrementitious  substances  can  be  produced  by  the  meta- 
morphosis of  other  substances,  and  by  the  addition  or  subtraction 
of  assumed  quantities  of  water  or  oxygen,  or  both;  but  the  whole 
matter  rests  upon  his  own  assumptions,  and  simply  shows  that  he 
is  as  capable  in  ingenuity  as  he  is  in  chemical  research.  Some  of 
his  formulas  are,  however,  very  plausible ;  and  when  we  take  into 
consideration  the  fact  of  his  assumed  quantities  being  taken  alone 
from  those  substances  (oxygen  and  water)  that  must  play  a  great 
part  in  nearly  every  chemical  metamorphosis  which  takes  place  in 
the  body,  we  cannot  but  be  led  to  think  that  he  has,  in  these 
formulae,  opened  up  a  road  which  will  lead  to  many  valuable 
truths. 

There  is  yet  to  be  considered  one  other  constituent  of  the  bile, 
cholesterme- — a  substance  which,  until  quite  recently,  has  been  little 
investigated,  but  which,  thanks  to  the  labors  of  Flint,  Jr.,  has 
become  better  known.  His  views  I  shall  presently  briefly  state, 
giving  them  as  I  find  them  in  a  paper  published  by  him  in  the 
American  Journal  of  Medical  Sciences,  for  October,  1862,  entitled 
"New  Excretory  Function  of  the  Liver." 

Oholesterine — whose  chemical  constitution  is  variously  put  down, 
some  making  the  formula  C25H220,  some  C37H32O,  and  others  as- 
serting still  higher  atomic  numbers — is  a  crystal lizable  substance, 
soluble  in  ether  and  boiling  alcohol,  but  sparingly  soluble  in  cold 
alcohol,  and  insoluble  in  water.  It  is  also  freely  soluble  in  the  fatty 


CHEMICAL    CONSTITUTION    OF    BILE.  19 

oils  and  in  tauro-cholic  acid,  and  hence  is  held  in  solution  in  the 
bile.  Salisbury  says  it  "is  soluble  in  9  parts  of  boiling  alcohol  of 
0.84,  and  5.55  parts  of  0.816 ;  in  12  parts  of  ether  at  32°  F.,  3.7  at 
59°  F.,  and  2.2  at  boiling;  it  is  also  soluble  in  wood-spirit,  slightly 
soluble  in  boiling  oil  of  turpentine  and  in  water  containing  4  parts 
of  dry  soap."  Cholesterine  is  classed  by  Lehmann  among  the 
lipoids  because  of  its  strong  resemblance  to  the  fats,  its  difference 
from  them  being  its  incapability  of  saponification.  It  separates 
from  its  solution  in  layers  of  beautiful  rhomboidal  plates,  whose 
extreme  tenuity  enables  the  observer  to  see  the  outlines  of  the 
lower  plates  through  the  substance  of  those  that  are  superposed 
(Dalton,  and  Flint,  Jr.).  An  aggregation  of  cholesterine  crystals  is 
one  of  the  most  beautiful  of  microscopic  objects.  Lehmann  gives 
the  angles  of  the  tablets  at  100°  30'  and  79°  30',  but  Flint  rejects 
the  view  of  these  angles  being  invariable,  he  having  found  them  to 
be  of  different  measurements ;  and  from  this  circumstance,  together 
with  observations  made  during  crystallization,  he  inclines  to  the 
opinion  that  the  tablets  are  not  regular  crystals,  but  rather  "frag- 
ments of  micaceous  sheets,  which,  from  their  extreme  tenuity,  are 
easily  broken."  Yirchow  has  made  out  that  the  chemical  reaction 
of  cholesterine  with  sulphuric  acid  and  iodine  is  the  same  as  that 
of  the  cellulose  of  plants ;  iodine  alone  produces  no  change,  but 
when  the  acid  is  added  to  the  iodized  mass,  "its  plates  become 
colored,  and  assume,  particularly  at  first,  a  brilliant  indigo-blue  tint, 
which  gradually  passes  into  a  yellowish-brown,  until  the  cholesterine 
is  converted  into  a  brownish  drop."  With  concentrated  sulphuric 
acid,  cholesterine  strikes  a  beautiful  purple-red  color  (Salisbury). 
Lehmann  states  that  cholesterine  becomes  electrical  on  friction. 
It  has  been  found  in  many  different  situations,  its  most  frequent 
habitat  being  the  bile,  blood,  liver,  meconium,  brain,  and  nerves.  The 
crystalline  lens  will  also  furnish  it  in  large  quantity.  Flint  denies 
its  presence  in  normal  feces,  though  others  are  said  to  have  found 
it  there.  We  find  it  in  many  pathological  products ;  it  forms  a 
great  part  of  biliary  calculi ;  in  fact,  I  recollect  a  case,  in  which  in 
the  gall-bladder  of  a  woman  there  were  found  seventy  two  gall- 
stones, which  were  made  up  of  pure  cholesterine;  in  cancer, 
encysted  tumors,  the  fluid  of  hydrocele  and  of  ovarian  cysts, 
tubercle,  epithelial  tumors,  pus,  degenerated  ovaries  and  testes,  and 
in  pulmonary  expectoration,  cholesterine  has  been  found  in  more 
or  less  quantity  (Lehmann  and  Flint).  I  have  met  with  it  in  can- 


20  PRIZE    ESSAY: 

cer,  in  the  fluid  of  ovarian  cysts,  and  in  atheromatous  matter.  Leh- 
mann  says  that  he  "  once  found  the  choroid  plexus  in  the  brain 
perfectly  incrusted  with  cholesterine,"  and  he  considers  it  to  be  "  an 
integral  constituent  of  pus."  I  have  known  pieces  of  abnormal 
brain  and  spinal  cord  that  had  remained  in  alcohol  fora  short  time 
to  become  quite  brilliant  from  the  numerous  crystals  of  cholesterine 
that  had  formed  on  their  surfaces.  Virchow  asserts  it  to  be  a  con- 
stant ingredient  of  atheromatous  matter,  and  further,  that  in  "  every 
case  where  fatty  products  remain  stagnant  for  a  considerable  time 
within  a  closed  cavity  in  which  but  little  interchange  of  matter  can 
go  on,  the  fat  sets  free  cholesterine"  (Cellular  Pathology).  Salisbury 
(see  April  number,  1863,  American  Journal  of  Medical  Sciences)  has 
found  cholesterine  in  numerous  situations  as  follows :  in  the  ova  of 
the  human  subject  and  of  animals;  in  the  seminal  fluid  of  man; 
in  the  saliva ;  in  the  effusion  from  congested  or  inflamed  mucous 
surfaces;  in  the  fluid  of  ascites  ;  in  the  fluid  of  spina  bifida  tumors ; 
in  the  tears;  in  the  rnilk  of  the  cow,  and  in  that  of  woman  before  and 
soon  after  delivery ;  in  butter,  beef,  and  hog  suet ;  in  the  secretion 
of  the  sudorific  glands,  and  in  the  urine  in  jaundice,  intermittent 
fever,  varicella,  diphtheria,  diabetes  mellitus,  remittent  and  typhoid 
fevers.  He  agrees  with  Flint  as  to  its  being  an  effete  product  of 
the  nervous  system,  but  thinks  his  observations  prove  that  the 
liver  is  not  the  only  organ  which  separates  it  from  the  blood.  The 
analyses  of  Flint  show  that  cholesterine  exists  in  much  larger 
quantity  in  the  blood  than  has  been  suspected.  While  Becquerel 
and  Eodier  obtained  only  .090  parts  of  cholesterine  in  1000  parts 
of  venous  blood,  Flint  was  able  to  obtain  as  much  as  .445,  .751,  and 
.658.  He  accounts  for  this  great  difference  of  results  on  the  ground 
that  while  others  operated  merely  on  the  serum,  he  operated  on 
both  the  clot  and  serum. 

Concerning  the  origin  of  cholesterine,  there  was  nothing  but  con- 
jecture until  Flint's  investigations.  That  this  statement  is  true,  it 
is  only  necessary  to  glance  at  what  has  been  said  on  this  subject 
by  leading  physiological  chemists.  And  it  seems  that  there  is 
every  reason  to  believe  that  Flint's  investigations  in  this  direction 
establish  as  truthful  his  proposition  that  "cholesterine  is  an  excre- 
mentitious  product  formed  in  great  part  by  the  destructive  assimi- 
lation of  the  brain  and  nerves."  It  will  be  interesting  to  briefly 
glance  at  some  of  the  proofs  by  which  he  seeks  to  establish  this 
proposition.  In  the  first  instance,  he  took  some  dog's  blood  from 


CHEMICAL    CONSTITUTION    OF    BILE.  21 

the  internal  jugular,  carotid,  vena  cava,  hepatic  veins,  hepatic 
artery  and  portal  vein,  in  the  order  in  which  they  are  named,  and 
extracted  the  cholesterine  from  each.  This  experiment  demon- 
strated to  his  satisfaction  that  there  was  a  much  larger  quantity  of 
cholesterine  in  the  veins  returning  the  blood  from  the  brain,  the 
pelvic  organs,  and  the  lower  extremities,  than  there,  was  in  the  ves- 
sek  carrying  the  blood  to  those  organs.  Now,  as  it  is  known  that 
the  nervous  tissue  is  the  only  one  that  normally  furnishes  choles- 
terine in  any  quantity,  it  should  seem  that  the  blood,  in  passing 
through  it,  must  acquire  the  cholesterine  from  that  tissue.  But 
Flint  was  not  satisfied  until  he  had  made  a  quantitative  analysis. 
For  this  purpose,  he  made  three  experiments  on  dogs,  taking  blood 
from  the  carotid,  internal  jugular,  and  femoral  vein  of  two  of  them, 
and  from  one  of  them  blood  from  the  two  former.  The  first  ex- 
periment demonstrated  that  there  was  an  increase  of  cholesterine 
in  the  blood  of  the  jugular  vein  over  the  arterial  blood  of  3.488 
per  cent.,  and  an  increase  in  the  femoral  vein  of  4.134  per  cent. 
Thinking  that  the  etherization  might  affect  the  nutrition  of  the 
nervous  tissue,  especially  that  of  the  brain,  he  operated,  in  the 
next  two  experiments,  without  administering  an  anesthetic.  In 
this  he  was  correct,  for  both  experiments  demonstrated  a  much 
greater  increase  of  cholesterine  in  the  venous  blood  over  the 
arterial  blood  than  did  the  first  experiment.  In  one  case  the 
increase  in  the  blood  of  the  jugular  vein  was  59.772,  and  in  that  of 
the  femoral  vein,  6.308  per  cent.  In  the  last  experiment  of  this  se- 
ries, the  increase  in  the  blood  of  the  jugular  was  23.307  per  cent.  I 
merely  sketch  here  what,  in  Flint's  paper,  is  drawn  out  in  admirable 
detail ;  but  sufficient  has  been  put  down  to  reasonably  prove  that 
cholesterine  is  acquired  by  the  blood  in  its  passage  through  the  ner- 
vous tissue.  There  is  still  other  proof,  however.  If  cholesterine 
be  the  product  of  the  destructive  assimilation  of  nervous  tissue,  it 
should  be  produced  in  proportion  to  the  activity  of  that  tissue ;  and 
in  cases  of  paralysis,  where  the  nutritive  forces  in  the  parts  affected 
are  so  much  interfered  with  that  the  tissue  sometimes  becomes  dis- 
organized, we  should  have  a  diminution  in  the  quantify  of  choles- 
terine of  the  venous  blood.  This  was  found  to  be  the  case.  Flint 
operated  on  hemiplegic  patients  by  taking  blood  from  both  arms, 
arid  analyzing  it  for  cholesterine.  It  is  well  worth  while  to  subjoin 
the  table  of  his  results : — 


22 


PRIZE    ESSAY: 


Blood. 
Grains. 

Cholesterine. 
Grains. 

Cholesterine  per  1000. 

Case  I. 

55  458 

The     watch-glass     contained 

128.407 

0.062 

0.031  grains  of  a  substance,  but 
the   most   careful    examination 
failed  to  show  a  single  crystal 
of  Cholesterine. 
0.4S1. 

Case  II. 
Paralyzed,  side 

18  381 

Same  as  Ca'se  I. 

66.396 

0.062 

0.808. 

Case  III. 
Paralyzed  side.... 

21.842 

Same  as  Case  I. 

Sound,  side  

52  261 

0.031 

0.579. 

Flint  reasserts  his  views  in  regard  to  cholesterine  in  his  recent 
work  on  physiology,  and  they  would  seem  to  rest  upon  a  tolerably 
secure  foundation.  In  cases  of  acholia,  the  unconsciousness,  deli- 
rium, and  coma  (the  cause  of  which  has  puzzled  all  the  observers) 
are  attributed  by  him  to  the  excess  of  cholesterine  in  the  blood,  pro- 
ducing a  condition  which  has  been  called  cholesteremia,  in  analogy 
to  uremia. 

Cholesterine,  then,  as  the  above  series  of  experiments  seem  to 
prove,  is  the  product  of  the  destructive  assimilation  of  nervous 
tissue  and  is  carried  by  the  blood  to  the  liver,  where  it  becomes  a 
constituent  of  the  bile.  In  the  former  it  is  thought  to  be  held  in 
solution  by  the  fatty  acids,  while  in  the  latter  the  biliary  organic 
salts  are  the  agents  which  render  it  soluble.  As  regards  this  sub- 
stance, it  is  interesting  to  cite  the  fact  that  it  is  the  only  one  of 
the  constituents  of  the  bile  proper  that  has  been  found  either 
in  the  blood  or  any  of  the  tissues.  And  though  this  by  no 
means  proves  that  its  fellows  are  formed  in  the  liver,  still  it 
should  have  some  weight  in  our  considerations  concerning  their 
origin,  and  when  our  attention  is  drawn  to  analogies  between 
the  kidney  and  the  liver,  we  must  keep  in  mind  the  fact  that 
every  organic  constituent  of  the  urine  has  been  found  in  certain  tis- 
sues and  some  of  them  in  the  blood;  while,  as  yet,  but  one  organic 
constituent  of  the  bile  has  been  so  found.  We  have  seen  that  the 
respective  constitutions  of  the  blood  of  the  portal  and  hepatic  veins 
will  account  for  the  origin  of  the  bile  ;  still,  as  our  blood  analyses 
are  not  yet  perfect,  our  present  knowledge  on  this  subject  can  be 
deemed  little  more  than  reasonable  conjecture. 

Tests  for  Bile. — The  peculiar  and  striking  play  of  colors  pro- 
duced by  treating  bile  with  nitric  acid  has  been  long  well  known, 


CHEMICAL    CONSTITUTION    OF    BILE.  23 

the  colors  passing  through  the  shades  of  blue,  violet,  red,  and 
green.  The  acid  should  be  applied  in  small  quantity  to  a  very 
thin  layer  of  the  suspected  liquid  if  we  wish  to  see  the  colors  in 
all  their  beauty.  If  the  acid  be  added  to  a  mixture  containing  bile, 
and  the  mixture  be  shaken  up,  a  dense  precipitate,  grass-green  in 
color,  will  be  thrown  down;  and  even  on  exposure  to  the  air,  in  an 
open  glass  vessel,  for  a  few  hours,  the  surface  will  gradually  assume 
a  greenish  tinge,  which  length  of  time  deepens  (Daltori).  If  muriatic 
acid  be  added  to  the  colored  liquid,  and  the  mixture  be  boiled  for  a 
short  time,  the  green  color  will  be  still  more  strikingly  brought  out 
(Brande  and  Taylor's  Chemistry}.  The  green  pigment  thus  produced 
has  been  called  biliverdin,  and  is  said  to  have  the  same  properties 
as  chlorophyll,  the  coloring  matter  of  plants.  It  is  highly  proba- 
ble that  the  nitric  acid  operates  by  oxidizing  the  cholepyrrhin,  as 
we  know  it  does  in  the  act  of  cauterization,  or  of  dissolving  those 
metals  that  are  unable  to  resist  its  power.  Nature  furnishes  us 
with  analogies.  The  beautifully  diversified  hues  that  the  leaves  of 
the  forest  assume  in  the  "  melancholy  days"  of  autumn,  are  the 
product  of  the  slow  oxidation  of  chlorophyll ;  the  vitality  of  the 
leaf,  kept  vigorous  by  the  breath  of  summer,  being  weakened  as 
the  chilling  breezes  prevail,  is  compelled  to  submit  to  the  play  of 
chemical  forces.1  The  haBmatin  preserves  its  color  when  circulating 
with  the  blood  in  the  vessels  of  the  body ;  but  when  the  blood  is 
extravasated,  its  pigment  is  overcome  by  the  chemical  forces,  and 
presents  all  the  colors  of  the  rainbow.  Nitric  acid,  however,  is  no 
test  for  bile — it  simply  reveals  the  presence  of  its  coloring  princi- 
ple;  and  if  the  latter  were  absent,  no  colors  would  be  produced. 
Some  other  test,  therefore,  is  necessary,  and  the  readiest  that  is 
known  to  chemistry  is  that  of  Pettenkofer.  This  consists  essen- 
tially in  the  reaction  that  the  bile,  or  its  chief  constituents  (the 
resinous  salts),  gives  with  sulphuric  acid  and  cane  sugar.  A  drop 
of  syrup  is  added  to  about  half  an  ounce  of  the  suspected  liquid, 
and  the  acid  then  added  until  a  red  color  is  made  manifest ;  this 

1  I  would  not  wish  to  be  understood  as  being  firmly  fixed  in  the  belief  that  vital 
effects  are  not,  or  cannot,  be  produced  by  physical  causes  ;  or  that  the  vital  princi- 
ple is  a  distinct  entity  which  stands  guard  over  the  tissues  and  controls  their 
action;  chemistry  has  produced  urea,  glycine,  taurine,  and  other  organic  com- 
pounds outside  of  the  body,  and  it  is  hence  reasonable  to  presume  that  they 
are  thus  produced  on  the  inside  of  it.  There  may  be  a  special  vital  force,  distinct 
from  the  other  forces  of  which  we  are  cognizant,  and  independent  of  the  control 
of  physical  law  ;  but  this  is  an  hypothesis,  which,  so  far  from  being  verified,  seems 
to  be  seriously  endangered  by  the  advance  of  science. 


2J:  PRIZE    ESSAY: 

slowly  passes  into  a  lake,  and  ultimately  into  a  purple.  If  the 
quantity  of  bile  is  very  small,  and  the  reaction  cannot  well  be  made 
out,  it  will  be  necessary  to  separate  the  resinous  salts  from  the 
mixture.  This  can  be  done  by  first  evaporating  to  dryness,  and 
then  treating  the  residue  with  boiling  alcohol ;  the  resinous  salts 
are  thus  dissolved  out,  together  with  the  coloring  matter,  choleste- 
rine,  and  more  or  less  of  the  fats.  The  alcohol  is  then  evaporated, 
and  the  residue  treated  with  a  small  quantity  of  ether ;  the  pre- 
cipitate at  first  produced  will  disappear  on  the  mixture  being 
shaken,  but  when  the  ether  is  added  in  excess,  the  precipitate 
remains  permanent,  and  consists  of  the  tauro-cholate  and  glyco- 
cholate  of  soda  (Dalton  and  Fowne).  These  latter  must  be  dissolved 
in  water  before  the  test  is  applied.  The  sugar  must  be  used  in 
very  small  quantity,  and  the  acid  cautiously  and  gradually  added, 
the  first  change  of  color  being  intently  looked  for.  As  soon  as  the 
first  tints  of  red  appear,  the  addition  of  the  acid  must  be  stopped 
(Dalton).  But  it  is  not  sufficient  to  indicate  the  presence  of  the 
resinous  salts  when  we  produce  the  red  reaction.  Unless  this 
color  pass  successively  into  lake  and  purple,  no  bile  is  before  us ; 
and  it  is  the  "lake  and  purple  color  alone  which  can  be  regarded 
as  really  characteristic  of  the  biliary  reaction"  (Dalton}.  As 
has  been  stated  before,  olein  is  susceptible  to  the  Pettenkofer  test; 
but  the  colors  are  much  longer  in  being  developed,  and,  as  Lehman  n 
remarks,  take  place  in  their  layers,  as,  for  instance,  on  a  watch-glass. 
Oil  of  turpentine  and  of  caraway  are  likewise  susceptible,  but  the 
red  color  becomes  brown  and  blackish,  and  a  tarry,  empyreumatic 
odor  is  produced.  Besides,  none  of  these  substances  are  likely  to 
be  found  in  the  animal  juices;  and,  moreover,  we  have  the  unfail- 
ing resource  of  extracting  the  organic  salts  from  the  suspected  liquid, 
if  they  be  present. 

Hoppe's  test,  of  which  mention  has  been  made,  is  more  delicate 
than  Pettenkofer's,  but  very  complicated,  and  is  as  follows : — 

"  1.  Decompose  the  icteric  urine  to  be  examined  with  an  excess  of 
milk  of  lime :  2.  Boil  for  about  half  an  hour ;  3.  Filter ;  4. 
Evaporate  the  filtered  fluid  nearly  to  dryness ;  5.  Decompose  with 
a  great  excess  of  concentrated  hydrochloric  acid,  and  then  keep 
the  whole  (before  being  again  filtered)  at  the  boiling  point  for  half 
an  hour;  6.  To  avoid  spurting  of  the  fluid,  it  is  necessary  to 
renew  the  volatilized  hydrochloric  acid  from  time  to  time ;  7. 
Leave  the  liquid  to  get  completely  cold,  and  then  add  six  to  eight 
times  its  volume  of  water ;  8.  Filter  the  dark  brown  turbid  solu- 


CHEMICAL    CONSTITUTION    OF    BILE.  25 

tion  thus  obtained,  and  wash  out  with  water  the  residue  on  the 
filter,  until  the  same  runs  through  quite  colorless;  9.  Dissolve 
the  brown  resinous  mass  on  the  filter  in  90  per  cent,  alcohol ;  10. 
Decolorize  by  boiling  with  animal  charcoal,  filter,  and  evaporate  to 
dry  ness  in  the  water  bath;  the  residue  is  a  yellow,  resinous  mass, 
which,  if  bile  acids  be  present,  must  consist,  for  the  most  part,  of 
pure  choloidic  acid.  In  such  a  case  it  melts  by  warming,  and  emits 
the  peculiar  musk  or  soap  odor.  11.  Lastly,  dissolve  in  a  very 
little  caustic  soda  and  some  drops  of  warm  water,  add  a  very  small 
piece  of  sugar,  and  allow  three  drops  of  concentrated  S03  slowly  to 
fall  into  it.  At  first  the  fluid  becomes  milky  and  troubled,  and 
resinous  flakes  separate,  which  stick  pertinaciously  to  the  glass, 
but  afterwards,  by  the  addition  of  more  S03,  these  again  dissolve, 
and  produce  a  beautiful  purple-red  or  dark  violet  fluid"  (Kuhne  as 
quoted  by  Aitken).  It  is  thus  seen  that  Hoppe  relies  upon  sul- 
phuric acid  and  sugar  the  same  as  Pettenkofer,  and  that  his  method 
consists  essentially  in  the  procurement  from  the  bile  of  choloidic 
acid  upon  which  to  use  those  reagents. 


Pamphlet 
Binder 

Gaylord  Bros.,  Inc. 

Makers 
Stockton,  Calif. 

PAT.  JAN.  21,  1908 


930873 


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